Diagnostic and Prognostic Values of miRNAs in High-Grade Gliomas: A Systematic Review

Background: Gliomas, particularly glioblastomas, have grim prognoses, necessitating early diagnostic and prognostic indicators. MicroRNAs (miRNAs), influential in cancer research, show potential as glioma biomarkers. This systematic review aimed to examine the efficacy of miRNAs in the diagnosis and prognosis of high-grade glioma. Methods: A comprehensive search was conducted of PubMed, EMBASE, Cochrane Library, and Web of Science for studies published from 2013 to 2023. The eligibility criteria included high-grade glioma, histopathological confirmation, miRNA samples from cerebrospinal fluid or plasma, and relevant outcome data. Studies were excluded if they were experimental or reviews and not in English. Results: Of the 1120 initial results, 8 studies involving 660 subjects met the inclusion criteria. Several studies have assessed miRNA expression and its association with diagnosis and prognosis of high-grade gliomas. Overexpression of miR-221, miR-222, miR-210, miR-21, miR-125b, and miR-223 and under-expression of miR-15b and miR-124-3p showed significant potential in differentiating high-grade glioma patients from controls. Additionally, miRNAs are associated with distinct tumorigenic pathways. Conclusion: Elevated or depressed expression levels of specific circulating miRNAs hold significant promise as noninvasive biomarkers for the diagnosis and prognosis of high-grade glioma. These miRNAs offer valuable insights into disease progression and patient outcome. Further validation through extensive clinical trials and in-depth mechanistic studies is essential to realize their full clinical utility.